As is known in the art, the roughness of the ocean surface is described by the convention of sea state and direction. There are several known sea state conventions, such as the World Meteorological Organization sea state code and the Douglas scale. United States Navy traditions for describing sea state have come from the “American Practical Navigator,” by N. Bowditch, while Europeans often specify sea state indirectly through reference to the Beaufort wind scale.
Related to sea state, but with more precision, is the notion of wave height described as “significant wave height” or Root Mean Squared (RMS) wave height. These descriptive single values summarize the scientific description of the ocean surface that requires a variety of parameters. In particular, the sea surface is more precisely described using spectral parameters of the waves.
As is known in the art, sea state estimation can be an important consideration in many applications, such as oil platform operation, safe boat handling, navigation, and sensor (radar) performance prediction. Traditionally, experienced mariners have visually estimated sea state, but this technique is somewhat arbitrary.